Persistent dorsal ophthalmic artery and ophthalmic artery arising from the middle meningeal artery diagnosed by MR angiography at 3 T

Permanent Vision Loss Due to Vascular Variation After Ear Hyaluronic Acid Injection: Two Case Reports and Literature Reviews

BACKGROUND

In line with modern aesthetic principles, a prominent and voluminous auricle is considered to enhance facial structure by making it appear smaller and more refined. Recently, there has been a growing trend toward using injectable treatments as an alternative to traditional surgical procedures for correcting lying ears. This shift has led to an increase in reported complications associated with these interventions.

OBJECTS

This report aims to investigate the mechanisms leading to vision loss following hyaluronic acid (HA) injections in the ear and to propose preventive measures and countermeasures.

METHOD

We present two rare cases of blindness following HA injections into the ears. The first patient experienced vision loss in both eyes, while the second suffered unilateral blindness in the left eye. In both cases, local hyaluronidase injections were promptly administered. Ophthalmological evaluations revealed central retinal artery occlusion, followed by arterial thrombolysis treatments performed 3 and 6 h post-diagnosis, respectively. Postoperative management included daily interventions to reduce intraocular pressure, promote vasodilation, enhance nerve nourishment, and provide hyperbaric oxygen therapy.

RESULTS

Digital subtraction angiography revealed structural variations in the ophthalmic arteries of both patients, which we hypothesize to be the primary cause of their blindness. In Case 1, the bilateral ophthalmic arteries and, in Case 2, the left ophthalmic artery were found to primarily originate from the external carotid artery. After treatment, Patient 1 exhibited a detectable index in the right eye, whereas the left eye was limited to light perception. Patient 2 showed recovery, with only defects in the inferior quadrant of the left eye.

CONCLUSION

The administration of filler injections in the auricular region is considered a high-risk aesthetic procedure due to the dense network of blood vessels and nerves, and significant anatomical variations. The use of large volumes of HA in this confined space can compress vascular structures and nerves, potentially leading to visual impairment. Therefore, ear filler injections are not recommended as a routinely substitute for the surgical correction of lying ears.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Carotid-anterior cerebral artery anastomosis with an anteromedial course variant diagnosed by magnetic resonance angiography

PURPOSE

To describe a case of right carotid-anterior cerebral artery (ACA) anastomosis with a unique course in the proximal segment.

METHODS

A 78-year-old woman with a history of right carotid endarterectomy 2 years prior underwent cranial magnetic resonance (MR) imaging (MRI) and magnetic resonance angiography (MRA) of the head and neck regions separately using a 3.0-Tesla scanner. MRA was performed using a standard 3-dimensional time-of-flight technique.

RESULTS

MRA of the intracranial region revealed no pathological lesions. However, a large artery arose from the ophthalmic segment of the right ICA, took an anteromedial course and after making a hairpin turn, continued to the bilateral A2 segments of the ACA. Bilateral A1 segments of the ACA were absent. MRA source images and oblique sagittal reformatted images showed that the anomalous artery was running inferior to the right optic nerve, indicative of carotid-ACA anastomosis or an infraoptic course of the ACA. As some patients have an ipsilateral normal A1 segment, the latter name seems to be inadequate.

CONCLUSION

We encountered a case of right carotid-ACA anastomosis in which the proximal segment had a unique course, ran anteromedially, and made a hairpin turn. This type has not been reported in the relevant English-language literature. Usually, this variation takes a medial course and ascends between the bilateral optic nerves. Careful observation of MRA images, including their source images, is required for the correct diagnosis of this rare variation.

Risk of Blindness From Temple Filler Injections: Investigating Vascular Anastomoses Between the Deep Temporal and Ophthalmic Arteries

PURPOSE

Soft-tissue filler injections, particularly hyaluronic acid, are popular for temple volume restoration. Although uncommon, this area poses risk for vision loss from embolic occlusion. Guidelines recommend injecting into the supraperiosteal plane for safety; however, the deep temporal arteries (DTAs) in this plane pose a risk. This study investigates potential pathways from the DTA to the ophthalmic artery (OA) and mechanisms of filler travel.

METHODS

Retrospective analysis of carotid angiograms from patients with marked carotid artery stenosis or vascular malformations, given that collaterals are more visible in the presence of vascular blockages. Select cases were identified by the neurosurgery team.

RESULTS

Four anastomotic pathways between the DTA and OA were identified, displaying a combination of anterograde and retrograde flow. Case 1 shows direct DTA-lacrimal artery anastomosis. In cases 2 to 4, the DTA is shown originating from the internal maxillary artery (IMAX) following its anatomical course. Retrograde flow from the DTA into the IMAX can then lead to anterograde flow into branches connecting to the IMAX including the superficial temporal artery, infraorbital artery, and middle meningeal artery. These arteries then form collaterals with the OA.

CONCLUSIONS

Our study is the first to elucidate 4 potential routes for filler-induced OA occlusion originating from DTAs in the supraperiosteal plane. These pathways involve retrograde flow, a mechanism previously suggested for filler-induced occlusion. Notably, the likelihood of these pathways being traversed may be low due to their length and amount of filler volume required; however, it is not impossible.

Regression of bilateral persistent primitive ophthalmic artery: a case report

PURPOSE

We report a case of regression of a 2-year-old girl with bilateral primitive ophthalmic arteries (POAs).

CASE REPORT

The patient presented with a headache and had no visual impairment or visual field abnormalities. Magnetic resonance angiography (MRA) revealed arteries originating bilaterally from the cavernous internal carotid artery segments, diagnosed as persistent POAs.

CONCLUSION

Six months later, MRA revealed decreased origin delineation and five years later, MRA revealed bilateral origin disappearance from the orbit to the periphery.

Frontal branch of the left middle meningeal artery arising from the ophthalmic artery diagnosed by magnetic resonance angiography

PURPOSE

A case of frontal branch of the left middle meningeal artery (MMA) arising from the ophthalmic artery (OA).

METHODS

A 73-year-old woman with vertigo underwent cranial magnetic resonance (MR) imaging and cranial MR angiography using a 1.5-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique.

RESULTS

MR imaging revealed multiple small ischemic white matter lesions. Maximum-intensity-projection (MIP) MR angiography showed no pathological arterial lesions such as steno-occlusive lesions; however, the left MMA arose from the OA. On MR angiographic source images, the tiny left MMA passed through the foramen spinosum and supplied the parieto-occipital trunk of the MMA. Thus, the left MMA arising from the OA was considered the frontal branch. The right MMA normally supplies both the frontal branch and the parieto-occipital trunk.

CONCLUSION

We present a case of MMA originating from the OA. The prevalence of this variation has been reported to be approximately 0.5%, which is not very rare. However, most reported cases are diagnosed using catheter angiography or cadaver dissection. We diagnosed this variation using MR angiography. Careful observation of MR angiographic source images is useful and important for identifying tiny arteries that cannot be visualized using MIP MR angiography.

The effect of arterial spin labeling MR angiography (ASL-MRA) in visualizing the branches of external carotid artery

This study aimed to assess the performance of arterial-spin labeling MRA (ASL-MRA) for visualizing the external carotid artery (ECA) branches in comparison with time-of-flight MRA (TOF-MRA) and CT angiography (CTA). We retrospectively selected 31 consecutive patients, who underwent both MRAs and CTA, prior to the intra-arterial chemoradiotherapy (IACRT) for head and neck cancer. Four patients underwent IACRT bilaterally, so we analyzed 35 ECAs. Pseudo-continuous, three-dimensional ASL using a turbo field echo sequence was acquired. For the TOF-MRA and CTA, clinically used parameters were applied. Two observers evaluated each ECA branch with reference to the angiogram at the IACRT, using five-point scale, in consensus. Friedman test for multiple comparisons was applied. ASL-MRA and CTA better visualized the superior thyroid, lingual, facial, submental, transverse facial, and internal maxillary arteries (IMAs) better than TOF-MRA (p < 0.05). In addition, CTA was superior to ASL-MRA in visualizing only submental artery among these arteries (p = 0.0005). Alternatively, the ASL-MRA was superior for visualizing the middle meningeal artery (MMA) and IMA, compared to the CTA (p = 0.0001 and 0.0007, respectively). ASL-MRA was superior to the TOF-MRA and similar to the CTA in visualizing most of ECA branches. Furthermore, ASL-MRA can better visualize the periphery of MMA and IMA than CTA.

Persistent trigeminal artery variant and presumed ophthalmic artery simultaneously arising from the inferolateral trunk incidentally diagnosed by magnetic resonance angiography

PURPOSE

To describe a case of persistent trigeminal artery variant (PTAV) and presumed ophthalmic artery (OA) simultaneously arising from the inferolateral trunk (ILT).

METHODS

A 53-year-old woman with an initial episode of convulsion underwent cranial magnetic resonance imaging (MRI) and MR angiography (MRA) of the intracranial region for the evaluation of brain and vascular lesions. The MR machine was a 3-T scanner.

RESULTS

MRI revealed no pathological brain lesions. On MRA, the left anterior inferior cerebellar artery (AICA) arose from the cavernous segment of the internal carotid artery (ICA), indicative of the PTAV. The arising point was more distal than the usual point, and the presumed OA also arose simultaneously from the short common trunk, which was considered the ILT.

CONCLUSION

There are two types of PTA: lateral (usual) and medial (intrasellar) PTA. The lateral-type PTA and PTAV arise from the ICA of the distal precavernous-proximal cavernous segment and take a course similar to that of the posterior fossa. The medial type arises slightly more in the distal cavernous segment than in the lateral type. The OA rarely arises from the cavernous segment of the ICA and enters the orbit via the superior orbital fissure. The origin of this type of OA is considered to be the ILT. We herein report a case of a PTAV and presumed OA arising simultaneously from an ILT. No similar case has been reported in the relevant English language literature.

External carotid artery to ophthalmic artery flow associated with internal carotid artery stenosis

PURPOSE

One of the most devastating complications of facial filler injection is sudden ischemic blindness. However, its mechanisms and predisposing factors are poorly understood. The purpose of this study was to investigate the prevalence of external carotid artery (ECA) to ophthalmic artery (OA) anterograde flow in patients with internal carotid artery (ICA) stenosis and in a control population without carotid disease.

METHODS

In this cross-sectional cohort study, two groups of patients who underwent catheter cerebral angiography over a 5-year period were identified: patients with symptomatic ICA stenosis and a control group of patients with refractory epistaxis undergoing embolization. Angiograms were reviewed by an interventional neuroradiologist. The primary outcome measure was the presence of ECA to OA flow, defined as choroidal blush before filling of the circle of Willis. Secondary outcome measures included the percentage and location of ICA stenosis and ECA anastomotic branches involved.

RESULTS

The study included 149 patients with ICA stenosis and 69 control patients. ECA to OA flow was more prevalent in patients with ICA stenosis (34.9%) compared to controls (2.9%) (p < .001). Logistic regression demonstrated that for each 10% increase in ICA stenosis over 70%, there was 2.8 times increased risk of ECA to OA flow (p < .001).

CONCLUSIONS

ECA to ICA anterograde flow can be demonstrated in approximately 3% of control patients and in over 1/3 of patients with symptomatic carotid stenosis. This provides a plausible pathway for small filler particles to pass with blood flow from the facial to the ophthalmic circulation.

Variants of the Anterior Subtemporal Approach to the Gasserian Ganglion and Related Structures: An Anatomical Study With Relevant Implications for Keyhole Surgery

BACKGROUND

The advantages and limitations of different craniotomy positions and approach trajectories to the gasserian ganglion (GG) and related structures using an anterior subtemporal approach have not been studied systematically. Knowledge of these features is of importance when planning keyhole anterior subtemporal (kAST) approaches to the GG to optimize access and minimize risks.

METHODS

Eight formalin-fixed heads were used bilaterally to assess temporal lobe retraction (TLR), trigeminal exposure, and relevant anatomical aspects of extra- and transdural classic anterior subtemporal (CLAST) approaches compared with slightly dorsally and ventrally allocated corridors.

RESULTS

TLR to the GG and foramen ovale was found to be lower via the CLAST approach (P < 0.001). Using the ventral variant, TLR to access the foramen rotundum was minimized (P < 0.001). The overall TLR was maximal using the dorsal variant (P < 0.001) owing to interposition of the arcuate eminence. An extradural CLAST approach required wide exposure of the greater petrosal nerve (GPN) and middle meningeal artery (MMA) sacrifice. Both maneuvers were spared using a transdural approach. Using CLAST, medial dissection >39 mm can enter the Parkinson triangle, jeopardizing the intracavernous internal carotid artery. The ventral variant enabled access to the anterior portion of the GG and foramen ovale without the need for MMA sacrifice or GPN dissection.

CONCLUSIONS

The CLAST approach provides high versatility to approach the trigeminal plexus, minimizing TLR. However, an extradural approach jeopardizes the GPN and requires MMA sacrifice. The risk of cavernous sinus violation exists when progressing medially beyond 4 cm. The ventral variant has some advantages to access the ventral structures and avoid MMA and GPN manipulation. In contrast, the usefulness of the dorsal variant is rather limited owing to the greater TLR required.

Ophthalmic artery arising from the external carotid artery system: the middle meningeal artery in South African patients

BACKGROUND

The ophthalmic artery is the first branch of the internal carotid artery. It arises from the supraclinoid segment of the internal carotid artery within the subarachnoid space and enters the orbit via the optic canal. However, due to complex embryogenesis, the ophthalmic artery can arise from different parts of the internal carotid artery or the distal branches of the external carotid artery. This is usually associated with a variation in the course of the ophthalmic artery through the superior orbital fissure instead of coursing through the optic canal. The ophthalmic artery and its branches vascularise the eyeball and its contents. Consequently, information about its morphologic variation is essential for treating clinical conditions such as central retinal artery occlusion, retinoblastoma chemoembolization, and ophthalmic artery aneurysm.

CASE PRESENTATION

We report on two cases of the ophthalmic artery arising from the middle meningeal artery in one adult (33-year-old Indian female) and one pediatric (2-year-old African male) South African patient examined by digital subtraction angiography. The patients were diagnosed with arteriovenous malformations and bilateral retinoblastoma, respectively.

CONCLUSIONS

The ophthalmic artery plays a vital role in vision generation. Thus, its anatomy is of clinical interest to neurosurgeons, ophthalmologists, and interventional radiologists.

Investigation into the ophthalmic artery and its branches by superselective angiography

BACKGROUND

The vascular anatomy of orbit is highly complex, and the main blood supply to the orbit is via the ophthalmic artery, which is a branch of the internal carotid artery. The purpose of this study was to determine the morphometry of the ophthalmic artery and its branches by superselective angiography in a large series of pediatric patients.

METHODS

We evaluated 134 angiographies performed on children with intraocular retinoblastoma undergoing intra-arterial chemotherapy. The origin, diameter, and angiographic visibility percentages of the ophthalmic artery and its branches were examined according to age group and sex.

RESULTS

The ophthalmic artery originated 97.8% from the internal carotid artery and 2.2% from the middle meningeal artery. The mean diameter of ophthalmic artery was measured 0.76 ± 0.14 mm in girls, 0.80 ± 0.15 mm in boys and 0.79 ± 0.15 mm in general. The posterior ciliary, lacrimal, inferior muscular, and anterior ethmoidal arteries had a higher angiographic visibility percentages (> 85%) than the other OA branches. Only the diameter of the dorsal nasal artery showed a significant correlation with age. The supratrochlear and posterior ciliary arteries showed statistically significant relationship with sex.

CONCLUSIONS

Present study will make a substantial contribution to the pediatric literature about the ophthalmic artery and its branches. A better understanding of ophthalmic artery morphology can help surgeons and neurointerventional radiologists to avoid possible severe complications during embolization, intra-arterial chemotherapy, cosmetic procedures, endonasal and orbital surgeries.

Ophthalmic artery arising from the presumed meningohypophyseal trunk of the cavernous internal carotid artery diagnosed by magnetic resonance angiography

PURPOSE

The purpose of the study is to describe a case of ophthalmic artery (OA) arising from the presumed meningohypophyseal trunk (MHT) of the cavernous internal carotid artery (ICA).

CASE REPORT

A 63-year-old woman suspected of having cerebral infarctions underwent cranial magnetic resonance (MR) imaging and MR angiography. MR angiography showed a right OA that was found to arise from the superolateral aspect of the proximal cavernous ICA. This OA entered the orbit via the superior orbital fissure (SOF).

DISCUSSION

Rarely, an OA arises from the inferior aspect of the middle cavernous ICA at the level of the inferolateral trunk (ILT) and enters the orbit via the SOF. This OA variation was traditionally regarded as a persistent primitive dorsal OA but is now believed to be due to the persistence of the lateral branch of the primitive maxillary artery. The present case had an OA arising from the superolateral aspect of the more proximal cavernous ICA than the origin of the ILT, which was suggested to be the origin of the MHT. Persistence of the proximal segment of the trigeminal artery may play an important role in the formation of this extremely rare variation.

CONCLUSION

To identify this extremely rare OA variation, careful observation of source images and the creation of volume-rendering MR angiography images are important.

Cerebral angiographic features of central retinal artery occlusion patients treated with intra-arterial thrombolysis

BACKGROUND

Central retinal artery occlusion (CRAO) is an ischemic stroke of the eye. The atherosclerotic lesions in the intracranial segment of the carotid artery (CA) and the ophthalmic artery (OphA) are not well defined. We aimed to investigate the cerebral angiographic features of CRAO patients and assess the relationship between the angiographic features and outcomes after intra-arterial thrombolysis (IAT).

METHODS

We included 101 acute non-arteritic CRAO patients treated with IAT. We analyzed the detailed angiographic features of the OphA and ipsilateral CA, visual acuity, fundus photography, and fluorescein angiography.

RESULTS

Of the 101 patients, 38 patients (37.6%) had steno-occlusive lesions in the OphA, and 62 patients (61.4%) had atherosclerotic lesions in the ipsilateral CA. The patients with a higher degree of stenosis in the OphA showed a higher degree of stenosis (P=0.049) and a more severe morphology of plaque (P=0.000) in the ipsilateral CA. Additionally, although the visual outcome was not associated with these angiographic features, the lower degree of stenosis and less severe morphology of plaque in the ipsilateral CA resulted in a significant improvement in early reperfusion rate (P=0.018 and P=0.014, respectively) and arm-to-retina circulation (P=0.016 and P=0.002, respectively) of the eye after IAT.

CONCLUSIONS

There was a significant correlation in the severity of steno-occlusive lesions between the OphA and the ipsilateral CA in patients with CRAO. The patients with less severe angiographic features in the CA showed a more improved retinal reperfusion after IAT. The angiographic findings in the CA may serve as a predictive marker for the vessel integrity of the OphA and recanalization outcome after IAT.

Relationship between internal carotid artery stenosis grade and optic nerve sheath diameter measured by transorbital ultrasonography

PURPOSE

To assess the consequence of the presence, grade, and asymmetry of carotid artery stenoses on the optic nerve sheath diameter (ONSD) measured by ultrasonography.

METHODS

ONSD was measured with B-mode ultrasonography in 129 patients referred for duplex and color Doppler imaging of the carotid arteries. Internal carotid artery stenosis was graded on the basis of peak systolic flow velocity.

RESULTS

The mean ONSD was 3.04 ± 0.38 mm in the patients without or with <50% internal carotid artery stenosis and 2.46 ± 0.35 mm in those with >70% stenosis. There was an average difference of 0.58 mm between the ONSD of the patients with <50% and the patients with >70% stenosis.

CONCLUSION

ONSD is lower in patients with carotid artery stenosis. Carotid arteries should be investigated, especially in patients with cardiovascular risk factors or diseases, before interpreting ONSD values.

Type 2 persistent primitive olfactory artery associated with bilateral ophthalmic arteries arising from the middle meningeal arteries diagnosed by magnetic resonance angiography

Persistent primitive olfactory artery (PPOA) is a relatively rare variation of the proximal anterior cerebral artery (ACA). Traditionally, there are two types: Type 1 is a common type, which generally follows an anteroinferior course and which takes a hairpin turn before continuing to the A2 segment of the ACA. Type 2 is an extremely rare variation that continues to the anterior ethmoidal artery without a hairpin turn. Since Type 2 PPOAs are small in caliber, previously reported cases were found during anatomical dissection or were detected by catheter angiography. We herein report a case of Type 2 PPOA that was diagnosed by partial-maximum-intensity projection images of magnetic resonance angiography. This patient also had bilateral ophthalmic arteries arising from the middle meningeal artery. These two variations may be related to each other.

Generation of Filler Emboli as a Mechanism for Filler-Related Blindness

BACKGROUND

Intra-arterial injection of fillers can lead to occlusion of the ophthalmic artery or its branches supplying the retina or the optic nerve. The mechanism through which this occurs is incompletely understood. We investigated the possibility of generating microparticles after injecting commercially available fillers into a flowing system in vitro.

METHODS

Three hyaluronic acid fillers and one calcium hydroxylapatite filler were injected into an artificial saline flow system mimicking arterial systolic blood pressure and corresponding to the diameter of the facial artery. All the saline at the end of the tube was collected, centrifuged, and inspected for filler particles.

RESULTS

After injection into the system, all fillers immediately disintegrated into small particles that were carried downstream with the flow of the saline. The saline at the end of the tube contained collections of filler.

CONCLUSION

Hyaluronic acid and hydroxylapatite fillers break up into small particles immediately after injection into a flowing system, generating emboli rather than a column of filler. The results of this study lead us to hypothesize another potential mechanism leading to filler-related blindness.

A systematic review of the surgical anatomy of the orbital apex

PURPOSE

The orbital apex is the narrowest part of the orbit, housing the link between the intracranial cavity and orbit. Knowledge of orbital apex anatomy is crucial to selecting a surgical approach and reducing the risk of complications. Our purpose is to summarize current knowledge on surgical anatomy and attempt to reach a consensus on definition of the orbital apex.

METHODS

The online databases of Embase, the Cochrane library, Web of Science and PubMed (MEDLINE) were queried in a comprehensive bibliographic search on the (surgical) anatomy of the orbital apex and consisted of a combination of two subjects, using indexed terms and free text: "Orbital Apex" and "Orbital Anatomy."

RESULTS

A total of 114 relevant papers were included in this review. Numerous anatomical variations are described in the literature. Variations of the optic canal include duplication (0.64%) and keyhole anomaly (2.65%). Variations in pneumatization of the anterior clinoid process were unilateral in almost 10%, bilateral in 9%, and normal in 72%. A rare variant of the superior orbital fissure (SOF) is Warwick's foramen, which appears as if the lowest portion of the SOF was separated from the main fissure by a transverse bony bridge.

CONCLUSION

The definition of the orbital apex varies in the literature, and further research would most likely identify additional variations. A universal definition reporting these variations and pathology and imaging findings is essential for determining the optimal surgical approach to the orbital apex.

Evaluation of the anastomoses between the ophthalmic artery and the middle meningeal artery by superselective angiography

PURPOSE

There are three anastomoses between the ophthalmic artery (OA) and the middle meningeal artery (MMA): the anastomotic branch with MMA, the recurrent meningeal branch and the anterior falx artery. We aimed to evaluate the anastomotic branches between the OA and the MMA on superselective angiograms of pediatric patients with retinoblastoma.

MATERIALS AND METHODS

We evaluated 126 angiographies performed on children with retinoblastoma. The mean diameter and angiographic visibility percentage of the anastomotic branches between the OA and the MMA were examined according to age group and sex.

RESULTS

The mean diameter of anastomotic branch with MMA was measured 0.58 ± 0.13 mm and we found this branch in 15 of 126 angiographic images (11.9%). We detected the recurrent meningeal branch in 47 of total images (37.3%). The recurrent meningeal branch arose 85.1% from the lacrimal artery, 8.5% from the anastomotic branch with MMA and 6.4% directly from the OA. The mean diameter of this artery was measured 0.21 ± 0.06 mm. Anterior falx artery was found in 86 of 126 angiographic peocedures (68.3%) and the mean diameter was measured 0.22 ± 0.06 mm.

CONCLUSION

Knowledge of the anastomoses between the OA and the MMA system are all necessary to perform safe and successful endovascular and surgical procedures involving the orbital region.

Embryology and anatomical variations of the ophthalmic artery

PURPOSE

The ophthalmic artery (OA) has one of the most complex anatomy and the most fascinating embryological development.

METHODS

The complexity of the embryologic development of the OA resides in the implication of three different embryological systems: the carotid system, the stapedial system, and the ventral pharyngeal system.

RESULTS

This explains very well the numerous variations in origin of the OA and the importance of vascular anastomoses developed with branches of the external carotid artery and with the middle meningeal artery.

CONCLUSION

In this review, authors propose a comprehensive description of different hypotheses on the embryologic development of the OA and, in a second part, explain all anatomical variations and clinical implications of this artery.

Bilateral anomalous origin of ophthalmic artery from middle meningeal artery and coincidence of bilateral carotid artery aneurysm: Case report and literature review

Ophthalmic artery (OA) is known for anomalous origin and aberrant course probably attributable to its complex embryology. Anomalous origin of OA can be associated with intracranial aneurysm. Anomalous origins have been reported from middle meningeal artery (MMA), cavernous carotid, posterior communicating, anterior cerebral and basilar artery. Even though bilateral anomalous origin of OA from MMA is a rare finding, to the author's best knowledge, association of above condition with bilateral internal carotid artery aneurysms has not been described in the literature. We present a case of such anomalous bilateral OA originating from MMA and associated with bilateral internal carotid artery aneurysms. We have also reviewed the pertinent literature regarding anomalous OA origin.

Double Ophthalmic Arteries Arising from the Internal Carotid Artery and the Accessory Meningeal Artery: A Case Report of a New Anatomic Variation

BACKGROUND

Variant origin of the ophthalmic artery (OA) is uncommon. The majority of variant origins are from the middle meningeal artery and from the infraclinoid segment of the internal carotid artery. An OA arising from the accessory meningeal artery is an extremely rare vascular variation that has not been described previously in the English literature.

CASE DESCRIPTION

We report the first case of double origin of the OA from the supraclinoid segment of the internal carotid artery and from the accessory meningeal artery branch of the maxillary artery. A 33-year-old woman was referred to our clinic with suspicion of a middle cerebral artery aneurysm. She had nonspecific neurologic symptoms. The patient underwent cerebral magnetic resonance imaging and magnetic resonance angiography.

CONCLUSIONS

Being aware of variant origin of the OA from the accessory meningeal artery is very important for transarterial chemoembolization in the external carotid artery territory. Reconstructed images from magnetic resonance angiography are very useful to reveal the variant origin of the OA.

Unusual ophthalmic artery origin: Implications for intraarterial chemotherapy of retinoblastoma

We report two pediatric retinoblastoma patients with unusual ophthalmic artery (OA) origins who were referred to our interventional neuroradiology department for intraarterial chemotherapy. The first patient had double OAs arising from the ipsilateral internal carotid artery and a central retinal artery (CRA) arising from the more cranially located artery, whereas the second patient had an OA originating from the A1 segment of the ipsilateral anterior cerebral artery. In both cases the CRA arose from the artery entering the orbit through the optic foramen. Both patients tolerated the procedures well. To the best of our knowledge, our retinoblastoma patients with unusual OA origins are the first in the literature in which detailed knowledge of the orbital vasculature and especially CRA origin carried immediate clinical implications, altering access strategies. These variations were proved both by flat-panel detector computed tomography findings and superselective injections of OAs with unusual origins. Our results show that in patients with retinoblastoma, a detailed angiographic work-up may be necessary to evaluate the orbital vasculature and possible abnormal origin of the OA. Recognition of possible variations of OA origin and its branching patterns is of the utmost importance for successful treatment and avoidance of adverse events among retinoblastoma patients.

Anomalous Origins of Ophthalmic Arteries on Three-Dimensional Time-of-Flight Magnetic Resonance Angiography and Their Clinical Importance

AIM

The purpose of this paper was to evaluate rare cases of anomalous origins of the ophthalmic artery (OA) according to magnetic resonance angiography (MRA) findings.

METHODS

This retrospective study included 80 patients diagnosed with anomalous OA origins between March 2015 and July 2018 from a sample of 16,024 patients. The patients included 47 females and 33 males with a mean age of 38.16 years (range 18-62 years). Three-dimensional time-of-flight (3D-TOF) MRA was performed for all patients.

RESULTS

Eighty (0.5%) patients had anomalous OA origins. The most common type of OA origin anomaly was the right OA originating from the middle meningeal artery (0.17%). Twelve (0.07%) patients had OAs with an extradural origin.

CONCLUSIONS

Anomalous origins of the OA are rare. 3D-TOF MRA is a noninvasive imaging method that can be applied for the diagnosis of OA anomalies. Some OA variations can have a protective effect against ocular complications in vaso-occlusive events. Therefore, it is critical to know the variant anatomy of OAs.

Carotid-anterior cerebral artery (ACA) anastomosis associated with azygos ACA and ophthalmic artery arising from the middle meningeal artery: a case report

Among variations of the anterior cerebral artery (ACA), anastomosis of its A1-A2 junction with the ophthalmic segment of the internal carotid artery is rare and described as carotid-ACA anastomosis or infraoptic course of the ACA. One common variant, an azygos ACA, demonstrates no pairing of the A2 segment. To our knowledge, association of a carotid-ACA anastomosis with an azygos ACA is not reported in the English-language literature. We report a case diagnosed by magnetic resonance angiography in which right carotid-ACA anastomosis was associated with an azygos ACA and the right ophthalmic artery originated from the middle meningeal artery.

The Three-Dimensional Computed Tomography Anatomic Features of Internal Carotid Artery-Ophthalmic Artery

OBJECTIVE

This research aimed at exploring the measurement of anatomic parameters of internal carotid artery-ophthalmic artery (ICA-OA) and the clinical significance with 3-dimensional (3D) separating, fusing, opacifying, false-coloring, and volume rendering (SFOF-VR) technique.

METHODS

A total of 109 patients with no significant lesions in ICA-OA were randomly selected, including 56 males and 53 females, who were divided into 3 groups: young age group (18-40 years, n = 36), middle age group (41-60 years, n = 40) and old age group (>60 years, n = 33). The 3D images were constructed by AW 4.6 workstation, and the anatomic parameters were measured. The SFOF-VR technique explicitly displayed ICA, OA, and their concomitant relationship with ophthalmic nerves (ONs) and adjacent structures. The study protocol was approved by the Medical Ethical Committee of Shaanxi Provincial People's Hospital and all patients have signed consent forms.

RESULTS

The diameters of initial segment of left and right ophthalmic ICA (ICA-C6) were 3.58 ± 0.51 mm and 3.58 ± 0.43 mm, respectively; the diameters of the left and right OA were 1.16 ± 0.16 mm and 1.15 ± 0.19 mm, respectively; the lengths of left and right ICA-C6 were 10.43 ± 2.08 mm and 10.01 ± 2.32 mm, respectively. There were statistically significant differences between bilateral ICA-C6 lengths, right ICA-C6 diameter, right OA diameter, and OA-ON space between male and female.

CONCLUSION

The SFOF-VR technique can distinctly present the structures of ICA-OA and adjacent tissues, providing valuable information for surgical operation. The 3D computed tomography data about ICA-OA can enrich references for basic and clinical researches.

Anomalies and Normal Variants of the Cerebral Arterial Supply: A Comprehensive Pictorial Review with a Proposed Workflow for Classification and Significance

Cerebral arteries may exhibit a wide range of variation from normal anatomy, which can be incidentally discovered during imaging. Knowledge of such variants is crucial to differentiate them from pathologies, to understand the etiology of certain pathologies directly related to a vascular variant, and to depict the changes in collateral circulation in patients with certain variants. Detection of particular variants may lead to the discovery of other nonvascular or vascular anomalies, especially aneurysms, and may also affect planning of endovascular or neurosurgical interventions. In this review, we summarize the variants and anomalies of cerebral arteries seen on cross-sectional imaging classified by a morphological approach and categorize their significance from a clinical perspective. This structured review is intended to serve as a guide for daily use in clinical practice.

An update on the variations of the orbital blood supply and hemodynamic

PURPOSE

Several variations of the arterial blood supply of the orbit have been reported over the years. This review is aimed to provide an update focusing on three important issues: (a) variations of the ophthalmic artery origin; (b) contribution of the external carotid artery to the orbital blood supply; (c) orbital hemodynamic.

METHODS

A PubMed and Google search was carried out with the following keywords: ophthalmic artery origin, ophthalmic artery anastomoses and ophthalmic artery anatomy.

RESULTS

The site of origin of the ophthalmic artery displays a limited number of variations. However they are important as they are also associated with course variations. Anastomoses between the ophthalmic artery and the external carotid artery are numerous and many of them can acquire clinical relevance. Records on their anatomic frequency are limited. Orbital hemodynamic variations are a poorly studied subject. Recent investigations in children have unveiled unexpected variability and instability in the way the blood flows through the orbit.

CONCLUSIONS

The orbit shows several possible arterial variations. Some of them have a profound influence on its hemodynamic at least in children. More studies are required to ascertain if the hemodynamic variability observed in children can be pinpointed also in adults.

Right persistent trigeminal artery variant (PTAV) and tiny left PTA associated with bilateral ophthalmic arteries arising from the cavernous segments of the internal carotid arteries

Persistent trigeminal artery (PTA) and its variant (PTAV) are the most prevalent types of carotid-vertebrobasilar anastomosis, but bilateral anastomoses are exceedingly rare. We report a case of a right PTAV and tiny left lateral-type PTA from which the cerebellar artery (presumed anterior inferior cerebellar artery) arose. And also, bilateral ophthalmic arteries arose from the cavernous segments of the internal carotid arteries and entered the orbits via the superior orbital fissures. Selective cerebral angiography, especially 3-dimensional angiography, is superior to magnetic resonance (MR) angiography to identify rare variations of the cerebral arteries. Careful observation of MR angiographic source images is important for identifying unique arterial coursing.

4D Flow MR Imaging of Ophthalmic Artery Flow in Patients with Internal Carotid Artery Stenosis

Background and Purpose:

To assess the clinical feasibility of time-resolved 3D phase contrast (4D Flow) MRI assessment of the ophthalmic artery (OphA) flow in patients with internal carotid artery stenosis (ICS).

Materials and Methods:

Twenty-one consecutive patients with unilateral ICS were recruited. 4D Flow MRI and acetazolamide-stress brain perfusion single photon emission computed tomography (SPECT) were performed. The flow direction on the affected-side OphA was categorized into native flow (anterograde or unclear) and non-native flow (retrograde flow) based on 4D Flow MRI. In the affected-side middle cerebral artery (MCA) territory, the ratio of rest cerebral blood flow to normal control (RCBF_MCA) and cerebral vascular reserve (CVR_MCA) were calculated from SPECT dataset. High-risk patients were defined based on the previous large cohort study (RCBF_MCA < 80% and CVR_MCA < 10%).

Results:

Eleven patients had native OphA flow (4 anterograde, 7 unclear) and the remaining 10 had non-native OphA flow. RCBF_MCA and CVR_MCA each were significantly lower in non-native flow group (84.9 ± 18.9% vs. 69.8 ± 7.3%, P < 0.05; 36.4 ± 20.6% vs. 17.0 ± 15.0%, P < 0.05). Four patients in the non-native flow group and none in the native flow group were confirmed as high-risk (Sensitivity/Specificity, 1.00/0.65).

Conclusion:

The 6 min standard 4D Flow MRI assessment of OphA in patients with ICS can predict intracranial hemodynamic impairment.

Anatomy of the Ophthalmic Artery: Embryological Consideration

There are considerable variations in the anatomy of the human ophthalmic artery (OphA), such as anomalous origins of the OphA and anastomoses between the OphA and the adjacent arteries. These anatomical variations seem to attribute to complex embryology of the OphA. In human embryos and fetuses, primitive dorsal and ventral ophthalmic arteries (PDOphA and PVOphA) form the ocular branches, and the supraorbital division of the stapedial artery forms the orbital branches of the OphA, and then numerous anastomoses between the internal carotid artery (ICA) and the external carotid artery (ECA) systems emerge in connection with the OphA. These developmental processes can produce anatomical variations of the OphA, and we should notice these variations for neurosurgical and neurointerventional procedures.

Ophthalmic artery originating from the anterior cerebral artery: anatomo-radiological study, histological analysis, and literature review

The ophthalmic artery has an anomalous origin in 2-3 % of cases and rarely arises from the anterior cerebral artery. Herein, we provide the first anatomical, radiological, and histological description of such an anomalous origin, together with a literature review. During the anatomical dissection of an 81-year-old Caucasian male, the absence of the right ophthalmic artery in its usual location was evident from an endonasal transsphenoidal perspective. The specimen was then studied in detail, through multiple dissections, corrosion casting, high-resolution CT, and histological analysis. The English literature on anomalous origins of the ophthalmic artery was reviewed, together with reported associated pathologies. Anatomo-radiological analysis documented that the right ophthalmic artery arose from the inferior surface of A1 tract of the anterior cerebral artery (A1) and passed over the optic nerve in its subarachnoid tract. A meningo-ophthalmic artery was evident on the same side and reached the orbit through the superior orbital fissure. Histological examination of both internal carotid artery (ICA) walls documented a significantly decreased thickness of the tunica media and adventitia on the side of the anomalous ophthalmic artery, with a significantly different content of collagen types I and III. The literature review documented an association of aneurysms and anomalous ophthalmic arteries. To the best of our knowledge, this is the first anatomical report that includes a radiological and arterial wall analysis of a persistent ventral ophthalmic artery. The latter provides histological data that support the clinical evidence of a higher association of aneurysms with anomalous origins of the ophthalmic artery.

Anatomy of the Ophthalmic Artery: A Review concerning Its Modern Surgical and Clinical Applications

Anatomy of ophthalmic artery has been thoroughly studied and reviewed in many anatomical and surgical textbooks and papers. Issues of interest are its intracranial and extracranial course, its branches, its importance for vision, and its interaction with various intracranial pathologies. Improvement of our understanding about pathophysiology of certain diseases like aneurysm formation, central retinal artery occlusion, and retinoblastoma and also invention of new therapeutic modalities like superselective catheterization, intra-arterial fibrinolysis, and intra-arterial chemotherapy necessitate a reappraisal of its anatomy from a clinical point of view. The aim of this review is to examine clinical anatomy of ophthalmic artery and correlate it with new diagnostic and therapeutic applications.

Ophthalmic artery arising from the anterior cerebral artery diagnosed by MR angiography

Extremely rarely, the ophthalmic artery (OphA) arises from the A1 segment of the anterior cerebral artery (ACA). Discovery of this anomalous OphA during angiography or surgery has been reported in several patients. We report a case in which an OphA of ACA origin was diagnosed by magnetic resonance (MR) angiography and confirmed by selective cerebral angiography. To our knowledge, this is the first report of this variation with MR angiography. Careful observation of MR angiographic images is important for detecting rare arterial variations. Partial maximum-intensity-projection images are useful in identifying tiny anomalous arteries on MR angiography.

Clinical anatomy of the orbitomeningeal foramina: variational anatomy of the canals connecting the orbit with the cranial cavity

PURPOSE

In addition to the optic canal and the superior orbital fissure, orbits are connected with the cranial cavity via inconstant canals including the orbitomeningeal foramen. This study has been carried out in order to define many anatomical and radiological details of the orbitomeningeal foramen that are relevant in the clinical practice.

METHODS

Almost 1000 skulls and 50 computerized tomographies were examined to determine incidence, number, length, and caliber of the orbitomeningeal foramen as well as the topography of their orbital and cranial openings. A retrospective study of angiographies carried out on more than 100 children was performed to look for arteries candidate to run through the orbitomeningeal foramen.

RESULTS

Orbitomeningeal foramina were detected in 59.46% of skulls and in 54% of individuals by computerized tomography. Orbits with two to five foramina were found. Canals were classified as M-subtype or A-subtype depending on their cranial opening. Large foramina, with the caliber ranging between 1 and 3 mm, were found in 12.17% of orbitomeningeal foramen-bearing orbits. By computed tomography the average caliber measured 1.2 ± 0.3 and 1.5 ± 0.5 mm (p < 0.005) at the orbital and cranial openings, respectively (p < 0.005). Angiographies showed meningo-lacrimal and meningo-ophthalmic arteries, meningeal branches of the lacrimal and supraorbital arteries, and some unidentified arteries that could pass through the orbitomeningeal foramina.

CONCLUSIONS

Orbitomeningeal foramina are a common occurrence. When large they may house important arteries that can be the source of severe bleedings during deep dissection of the lateral wall of the orbit. Orbital surgeons should be aware of their existence.

Different ophthalmic artery origins: Embryology and clinical significance

This retrospective study gives a summary of ophthalmic artery (OA) variations to serve as guidelines for surgical interventionists and trainees. Pubmed and Medline searches were conducted. The OA usually arises intradurally (superomedial, anteromedial, or rarely superolateral) from the internal carotid artery (ICA). Rare extradural origin (primitive dorsal OA) (PDOA) remnant and extremely rare interdural origin (primitive ventral OA) (PVOA) remnant are of significance when sectioning the dural ring. Rarely, a persistent PDOA with ICA origin, or a PDOA remnant with inferolateral trunk origin, enters the orbit via the superior orbital fissure (SOF) for sole or partial orbital supply. Extremely rare, the PDOA and PVOA persist and form double OAs that arise from the ICA and run via the SOF and optic foramen. Occasionally, the OA arises from the middle meningeal artery (MMA), when both the PDOA and VDOA regress and enter the orbit via the SOF. Sole orbital supply via the external carotid artery (ECA), i.e. meningo-ophthalmic artery and/or MMA branches, or dual OAs (ECA and ICA origins) may occur. Other rare OA origins include anterior or posterior communicating artery; anterior or middle cerebral artery; basilar artery; posterior inferior cerebellar artery; and the carotid bifurcation. Primitive arteries (persistent or remnant), and/or abnormal anastomoses play pivotal roles in manifestations of OA variations. Of clinical importance are orbital collateral routes and dangerous extracranial-intracranial anastomoses. Awareness of OA origins and collateral routes is imperative for transarterial embolizations or infusion chemotherapy in the ECA territory to prevent visual complications.

Cerebral Arterial Variations Associated with Moyamoya Disease Diagnosed by MR Angiography

Moyamoya disease is a rare progressive cerebrovascular steno-occlusive disease associated with different variations of the cerebral arteries. We evaluated the types and prevalence of such variations among patients with moyamoya disease. In our institution during the past seven years, we diagnosed 72 patients (24 male, 48 female; aged 6 to 75 years, mean, 42 years) with moyamoya disease by magnetic resonance (MR) angiography using either a 3-Tesla or one of two 1.5-T imagers and a standard time-of-flight technique without contrast media. An experienced neuroradiologist retrospectively reviewed the images. There were 15 cerebral arterial variations in 13 of 72 patients with moyamoya disease (18.1%), including four basilar artery fenestrations, three ophthalmic arteries arising from the middle meningeal artery, two intracranial vertebral artery fenestrations, two persistent first cervical intersegmental arteries, two persistent trigeminal arteries, one extracranial origin of the posterior inferior cerebellar artery, and one persistent stapedial artery. Although our number of patients was small, moyamoya disease was frequently associated with variations of the cerebral arteries, especially fenestrations in the vertebrobasilar system and persistent trigeminal artery.

Navigational area of the cranio-orbital foramen and its significance in orbital surgery

The cranio-orbital foramen (COF) is located on the lateral wall of the orbit. It is a potential source of hemorrhage during deep lateral orbital dissection, since it functions as an anastomosis between the lacrimal artery and the middle meningeal artery. The aim of this study was to guide and facilitate the surgical procedures in the orbit, so as to determine a navigational area and the precise location of the COF and to standardize certain anatomical marks. The navigational area of the COF and topographical features were studied in 75 craniums with presented COF. 33 bilateral main COFs, 41 (18 on the right, 23 on the left) unilateral main COFs at the main cranium and 19 accessory COFs were studied for their navigational features on the orbit. The distances between the COF and the fronto-zygomatic suture, supraorbital notch, lateral angle of the superior orbital fissure (SOF) and Whitnall's tubercle were measured. The mean distance of the COF from the fronto-zygomatic suture, supraorbital notch, lateral angle of the SOF and Whitnall's tubercle was 26.3, 37.3, 92 and 27.1 mm, respectively. For the navigational area signs of the COF, areas of the orbit that form the transversal and vertical lines are generated on the reference points. Whilst the upper outer area of the orbit contains a potential bleeding risk, the bottom section of the outer column is identified as safe for the surgical operations of the lateral orbital wall. The fronto-zygomatic suture and Whitnall's tubercle are recommended as the most reliable navigational landmarks for identifying the COF. Hence, the transversal and vertical orientation of the COF should be mastered by the surgeons reconstructing the anterior base of the skull and the orbit.